Automatic fluid cooled grate



May 6, 1941. G. w. WALLACE AUTOMATIC FLUID COOLED'GRATE F115@ may 2. 1938 3 Sheets-Sheet 1 INVENTOR May 6, 1941. G. w. WALLACE` 2,240,590

` AUTOMATIC FLUID cooLED @RATE Filed may 2, 19:58 s sheets-sheet 2 INVENTOR FIGJO.

FIG l1 1938 3 Sheets-Shet 3 v21. w. WALLACE AUTOMATIC FLUID COOLED GRATE Filedl May 2,

May s, 1941.

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Patented May 6, 1941 UNITED STATES PATENT OFFICE aurom'rrcrhomn anni: V i

George W. Wallace, East St. Louis, Ill. Application May 2,1938, Serial No. 205,416

3 Claims.

-This invention relates to. an improved automatic fiuid cooled grate and has for its principle object to provide a satisfactory grate which may be used as an integral part of an apparatus for carbonizing and distilling coals, lignites, oil s hales .or similar carbonaceous materials, by direct contact with hot gases passing down through the same.

Another primary object is to provide an automatic grate or stoker, which may be used to burn coal or other fuels at a high rate of combustion under severe temperature conditions.

Still another object is to provide a grate which is adapted to combining the operations of destructive distillation and combustion without requiring a separate grate, carbonization and combustion chamber.

A still further object is to provide a satisfactory water cooled grate bar which may be used in a grate assembly `consisting of a grate bars.

A further object is to provide e. grate for the above purposes which is comparatively inexplurality of such Figure 6 is a vertical cross section on line 6-6 Figure 5.-

Figure 7 is a vertical sectional view of still ani other type of water cooled grate bar which may be used in a water cooled grate assemblydand shows a single large ,water channel o r passage cast into the bar.

Figure 8 is a vertical cross` section on line 8--8 Figure 7. v

Figure \9 is a broken view in lplan of a portion of 'a grate assembly showing the grate bars inthe position occupied after advancing fresh material into the chamber.

Figure l0 is a broken view in plan of the grate assembly, Figure 9, showing two grate bars pulled out.

Figure l1 is a rview in plan of the grate assembly `*Figure 9, showing ve of the grate bars pulled` out.

Figure 12 is a view-in'plan of the grate assembly Figure 9, showing all of the grate bars Pulled out and in position to feed fresh maport the material, being carbonized or burned,

into and'through the chamber.

Figure 1 of the drawings is avertical sectional l 'view of one type of water cooled grate bar that may be used in practicing the present invention. Figure 2 is a vertical cross` section on line 2 1 Figure 1, showing rectangular water channels or passages through the grate bar.

Figure 3 isa vertical sectional view of a slightly diierent type of water cooled grate bar which may be4 used in the grate assembly of the present invention.

Figure 4 is a vertical cross section on line l-I Figure 3, and shows roiznd water channels or passages cast into the grate bar. r.

Figure 5 is a vertical sectional view of a water cooled grate bar which may be used in which the `arrangement .of the water channels is slightly different.

terial into the chamber.

Figure 13 is a vertical sectional View of the Water cooled grate housed within a carbonizing chamber on line |3|`3 Figure 14.

-Figure' 14 is a vertical section on line M-M Figure 13.

, Referring to the drawings in which all numerals referV to similar elements and which illustrate the preferred form of the present invention in which the automatic water cooled grate consists `of a plurality of water cooled grate bars similar `in type to the bars illustrated in Figures 1 to 8 inclusive. Figures i and 2 show a. metal grate y bar Iprovided with channels or passages 2 and 8 which are connected at the end of the bar by return bend 6-through which water'is caused to circulate. The water supplied to the grate bar is regulated by valve 4 passing through flexible connections i (in the illustration a flexible hose) into and` through the upper channel 2 at the .front end of the bar, and is returned through the lower channel 3 by return bend 6 and flexible connection I to manifold discharge 8. The grate bar is provided with a raised vertical or nearly vertical feeding face In for pushing the material being carbonized or burned into the carbonization orcombustion chamber from hopper` li. The upper'surface of the grate bar l2 forms a seal with the iront of the hopper il. A shown in Figure l the grate bar is pulled out. VAAny suitable means for reciprocating the y plurality oi state bars may be used for instance in Figure I. a rack I3 which is moved back and forth by segments of pinion gears I4 and I5 is shown.- The grate bar may be inclined near the rear end I8 if desired for-the purpose of increasing the depth of material on the grate.

A slightly different grate bar is shown in Figure 3 which may be used if desired in the grate assembly, in this illustration, the. baris stepped down one or more places i1 for the purpose of loosening the material passing through the chamber on the grate and in this illustration the grate makes it possible to carbonize coal, lignite, oil

shale o'r like carbonaceous materials continuouscarbonizing, the grate I is housed Within a suitbar is shown as being moved by a double acting cylinder and piston I8 which may be actuated by water, oil, steam, or air pressure.

The cooling water may be circulated through the'grate bars in any practical manner, for instance the upper and lower Water channels may extend through the bars and be connected at the rear'end with a'return bend 6 as shown in Figure or a single channel or passage may extend bars through valves l and connections 5,

The grate bars may be made of any suitable metal or alloy and the channel or passages pro- `vided for circulating water may be formed in any suitable manner; one method which vhas been found to bel satisfactory is to cast the grate bar around pipe or' tubing of the desired size and.

shape, or alternately the channel may be formed in a casting by using a core of the desired shape.

Inutilizing `the present invention in' its preferred form a plurality of water cooled grate bars are 'arranged to form a grate of the desired length, width and area, and suitable meansare provided for moving'the individual bars back and forth. Among the possible meansy two practical methods have been shown in the drawings.

In the preferred method of operation allof the grate bars aremoved in toward the rear of the carboniza'tion or combustion chamber at the same time and spe ed,lthev raised faces I0 of the grate bars remove a regulated amount of ma'- terial from hopper Il which is carried on the grate bars i into' the chamber.

Figures 1, 3, 5, and 12 show the grate bars pulled out and in position to move in, toward the rear of chamber, with fresh material.

After the grate bars have moved in they are brought out Ain sequence, no two adjoining grate bars being moved out at the same time. Figure 9 shows al1 of the grate bars in the position occupied after moving a fresh supply of material into the chamber. Figure shows the rst move following delivery of freshmaterial into the chamber, here two grate bars C and F have been moved out with two stationary grate barson'each side. Thek second Vmove is shown in Figure 11, `here three more grate bars A, D, and G have beenA l material. With this operating cycle the material on the grate is not drawn back when the grate able carbonizing chamber such as the chamber shown in Figures 13 and 14 of the drawings, in which 20 shows one form of carbonization chamber which would be suitable for the purpose, 2| represents an inlet or-inlets for the hot gases used to effect the carbonization, a space 22 is shown which may be used as a temperature equalizing chamber, or ifdesired as a combustion chamber. Any suitable type and character of hot gases may be used at any temperature that is practical. l

One or more receptacles or cells are provided below the grate into. which the products of the carbonization along with the hot gases used to effect the carbonization are drawn by a partial vacuum or are forced under a slight pressure, in

the drawings Figure 13 iive cells, 23 to 21 inclusive are shown .for this purpose.

The gases and products leave the Acarbonizing -apparatus through a series of valves 28 which of different places in the material. The valves 28 connect with gas manifold 29 which connects with a gas exhauster. The material is fed from hopper I I o nto the grate and through the cham ber the residue of the carbonization being discharged into hopper 30.

This arrangement permits the use of a grate having a large area and providesa rapid and economical methodof carbonizing a large tonnage of semi-bituminous coals, lignites or il shales as it provides a grate which will withstand the temperatures required anduused in an operation of this character. Grates which are not cooled may operate for a short time without trouble or replacements but must be operated at a, temperature below that required for greatest eiiiciency. With the present 'grate the temperature of the gases passed down through the same at any one point may be as high as is required without danger to the grate and the regulation can be made to suit the carbonizing reactions instead of being restricted to that. required to protect the grate.

'I'he grate of the present invention is suitable for use in my co-pending application No. 204,048.

Where the grate is used for combustion purposes in a power plant it will be arranged in a combustion chamber in the usual manner. The

areaof the grate will be determined by the size Vof the boiler installation and fuel requirements of the combustion` chamber. Cells may be provided under the grate tok furnish a distributed supply of air under a forced draft of regulated intensity. The grate and cells shown in Figure 13 would be similar to the arrangement .required 4 for combustion, the cells in this case being used bars are moved out and any disturbance of the material is reducedtoa minimum.

The present invention providesa grate which to regulate the air supplied below the grate to the different parts of the fire bed.

The water cooled grate of the present invention may be used to accomplish another novel operation. It may be used in an apparatus designed to combine the operation of destructive distillation or carbonization and combustion in pending on the products be inclined from the front tothe back. Where aaaasoo one operation as follows: The material to be destructively distilled and burned is fed onto the grate 'and throughthe combustion chamber in the manner hereinabove'described and burned in' the usual'way using forced draft, or if desired, natural draft; however, in this dual operation, the first cell 2l or cells 23 and 2| Figure 13 at the front or feed end of. the com`- bustion chamber are. connected with a gas ex hauster and a partial vacuum is carried in these cellsv which will vdraw a controlled amount of the hot combustion gases from the. combustion` chamber down through the fuel yas soon as it enters the chamber in this manner a large percentage" of the oils and gases usually formed or resulting from the destructivedistillation of carbonaceous fuel materials will be produced and after condensingthe oils the gaseous products may be returnedto the combustion chamber. Cells, 28. and 2l Figure 13 with additional cells if required. are used'to furnish the .air re-v quired under forced'or natural draft,A to comlpiete the .combustion of th fueiarter ninas passed through the distillation zone. Such a dual operation could not be carried ,on in the r/nanne'r described without using a water cooled grate such as the grate constituting the present invention. i 2

Utilizing the above described dual operation a large quantity of oil can be recovered from coals has been described in detail; however, the method of feeding the material ontor the grate and through the carbonization or combustion chamber may be varied from the preferred method.

for. instance a -separatefeeder may beused to 'move the material which feeder would have the same action as the feeding faces of the grate barsv as `shown in the 'drawings or a series of plungers or rams may be used forthepurpose each `of which would be arranged to feed material to one or more grate bars.

- ferent method of feedingmate'rial into the carbonization or combustion chamber the movement I i of the grate bars could b e arranged in a difieror lignites at low cost as a by-product in the `manufacture of-power which in many localities would be' a very important matter. i Where oil shales vare distilled this dual applicationmay be of great value to the localities where oil shale deposits occur.l .Normallywhen oil shale is disent sequence to that shown in the drawings.V

Ordinarilythe most practical way of cooling the bars of the grate would he by circulating water through the same, however, in some in' i resent the principle applications of the invention.`

I claim:

1.- In the destructive distillation and combustion oi' a layer offuel materials passing throughV a combustion chamber, a water cooled grate comprising'a plurality 'ofseparately mounted indiv vidually reciprocating grate bars each of which is provided with an internal channel through tilled the waste heat 4vand gases'including the free carbon in the spent shale is lost. The use of the present grate in the combined distillation and combustion apparatus will permit the ex.- traction of the oil from the shale and the conversion of the waste and other heat valuesl of the shale into power. The combustible matter.

in the spent shale will be completely burned;

leaving a shale residue which 'from certain shales gives an added value to the products. A water cooled grate such as the grate. of this invention is essential for such an operation. l

Any required number of grate barsmay be used in a grate assembly, however in practice four'bars would probably be the minimum num-` ber used and in this case the two outside bars spaced 'transversely extending separate cells, some of which are under suction and others of which which water is circulated, said grate being arranged tol receive, support, and move the material through' the combustionchamber over a series of separate cells over which the material passes, the ilrst cells being under suction and the rest .used to supply airto the material under forced draught.

2. A carbonizing retort comprising a combustion chamber having a plurality of longitudinally are under forced draft, a reciprocable grate mounted upon and extending in closurewlse rela might be stationary if desired. Where a relatively small number of bars are used they may be installed in a well or retort provided with air tuyres along the sides of-the grate.

In the drawings the grate'is shown in a horizontal position. 4Withsome materials and deproduced the gratemay the material has a tendency to move lwith dimculty through the chamber the grate would `be inclined down. .It is concelvable,'that where a non-uniform thickness of material is desired,

that the grate mightbe inclined u In the preferred form2 of assembling a plu-I, rality of reciprocating water cooled grate bars ing fluid and the other channel being connected tionshipover said cells, the grate having longitudin'ally spaced apertures, each of which is normally disposed in registration with one of said cells, said apertures' being of such size and position in relation to the cells as to be shifted into registration with a different cell upon reciprocation of the grate. Y f

v 3; In a carbonizingiretortof the character described. a grate consisting of a plurality of longitudinally shiftable grate bars each having an internal duid-circulating cooling channel having longitudinally extending spaced legs connected at one end by a reverse bend, one of, said .channels being connected at its other end by means' of a flexible tube to an individual source of coolby iiexibletubing to .a discharge manifold com.V mon to all of the grate bars. e

GEORGE W. WALLACE.

With a. dif- 

